I get that when I try to open FL files with Fruity Studio and then back to FL (Dont ask why). Try downloading Fruity Studio and using it to open the file.
You may get luck and get the sequence out of it although it usually looses the sample association on the sequencer.
If u dont have Fruity studio u can email me the file. I'll try and open it for you and send you the MIDI file. You can work wiv that. Mailto:seyi@6mics.com